Valuation of Variance Swaps in Volatile Markets with Regime Switching

Stochastic differential equations (SDEs) are extensively used to model various financial quantities. In the last decades, financial modeling by SDEs under regime-switching have been utilized to allow moving from an economic state to another. The aim of this research work is to tackle the pricing of variance swaps in a volatile market under regime switching model. SDEs under regime-switching models are more realistic but the solution is more complicated and may not exist analytically. Therefore, numerical methods for finance are explored. The study proposes a new SDE under regime-switching with high volatility model for the prices of the underlying financial asset. The suggested model combines two existing models, the first one is on high volatile situations and the second is on regime-switching. Under these setting, the valuation of variance-swaps is investigated. As an application, a study of two states is developed: state A when the economy is going well and state B when the economy is under stress. Numerical techniques for finance are employed to obtain a solution for the pricing problem. Several illustrations of the solution are provided and show the efficiency of the used methods

Phytochemical analysis and antioxidant activity of Haloxylon salicarnicum, Ochradenus arabicus and Tamarix nilotica

In the present investigation, the preliminary phytochemical analysis and antioxidant potential of hexane, chloroform, acetone and methanol extracts of Haloxylon salicarnicum, Ochradenus arabicus and Tamarix nilotica were reported. The presence of flavonoid, alkaloid, phenols, terpenoids, carbohydrate, tannin, protein, steroids, saponin, phlobatannin, cardiacglycoside, anthraquinines and volatile oils were determined and for antioxidant activity, DPPH, ABTS, superoxide anion radical and hydroxyl radical scavenging potential were studied. Strong presence of alkaloid, tannin, steroids in H. salicarnicum, flavonoid and phenols in O. arabicus and saponin T. nilotica were observed. In the present investigation, all the extracts inhibited the free radicals the methanol extract of O. arabicus was identified as potential crude extract compared to all other extracts with the IC50 values of 91.65 (DPPH), 94.62 (ABTS), 95.82 (O2) and 96.02 (OH) µg/mL. Whereas, the IC50 value of the standard, Gallic acid were 125.25 (DPPH), 142.32 (ABTS), 130.78 (O2) and 139.93 µg/mL (OH). Whereas, the IC50 value of the standard, Gallic acid were 125.25 (DPPH), 142.32 (ABTS), 130.78 (O2) and 139.93 µg/mL (OH)The present study suggests that methanol extract of O. arabicus can be used for the isolation potential natural antioxidant

A Comparative Study of Energy Performance in Educational Buildings in the UAE

Sustainability has gained popularity and importance around the globe due to the ever-increasing effects of climate change and global warming on Earth. As of the 21st century, human endeavour has caused an enormous amount of damage to the environmental ecological system. Among which, one of the major contributors to the increase in the environmental issues and CO2 emissions are the conventional sources of energy, especially in the built environment. Globally, the built environment accounts for 12 percent of the world’s drinkable water, 40 percent of energy wastage and 35 percent of scarce natural resources, which in turn produces 40 percent of the total global carbon emission. Among which are educational buildings which tend to be a major contributor (as most of these facilities are old and conventionally built in the mid-1900s) Thus, with the education sector being an essential part of society, it becomes important to determine the energy performance and carbon footprint of these buildings. The United Arab Emirates (UAE) vision 2021 highlights the country's approach to the importance of providing the best education and adopting sustainable environmental infrastructure. Therefore, this study adopts a methodological approach based on semi-structured interviews and surveys, in order to compare the energy performance of three educational buildings within Higher Education establishments in the UAE as a case study. The study also evaluates the end user’s awareness of the importance of sustainable practices in the buildings and their preference for these buildings. The findings of this study conclude that Net Zero Energy Buildings (NZEBs) are the most efficient buildings in terms of energy performance, carbon consumption and heat generated. Therefore, it is important that the integration of these types of buildings is considered in educational establishments

Analysis of SARS-CoV-2 viral loads in stool samples and nasopharyngeal swabs from COVID-19 patients in the United Arab Emirates

Coronavirus disease 2019 (COVID-19) was first identified in respiratory samples and was found to commonly cause cough and pneumonia. However, non-respiratory symptoms including gastrointestinal disorders are also present and a big proportion of patients test positive for the virus in stools for a prolonged period. In this cross-sectional study, we investigated viral load trends in stools and nasopharyngeal swabs and their correlation with multiple demographic and clinical factors. The study included 211 laboratory-confirmed cases suffering from a mild form of the disease and completing their isolation period at a non-hospital center in the United Arab Emirates. Demographic and clinical information was collected by standardized questionnaire and from the medical records of the patient. Of the 211 participants, 25 % tested negative in both sample types at the time of this study and 53 % of the remaining patients had detectable viral RNA in their stools. A positive fecal viral test was associated with male gender, diarrhea as a symptom, and hospitalization during infection. A positive correlation was also observed between a delayed onset of symptoms and a positive stool test. Viral load in stools positively correlated with, being overweight, exercising, taking antibiotics in the last 3 months and blood type O. The viral load in nasopharyngeal swabs, on the other hand, was higher for blood type A, and rhesus positive (Rh factor). Regression analysis showed no correlation between the viral loads measured in stool and nasopharyngeal samples in any given patient. The results of this work highlight the factors associated with a higher viral count in each sample. It also shows the importance of stool sample analysis for the follow-up and diagnosis of recovering COVID-19 patients

Comparing viral loads in stools and nasopharyngeal swabs of patients infected by different SARS-CoV-2 variants.

(a) negative for S protein mutations (b) N501Y mutation, (c) N501Y+K417N+E484K mutations, and (d) L452R mutation. The graph presents the median and the minimal to the maximal range of viral load in log10 copies/mL. The significance of the pairwise two-sided t-tests is indicated on top.</p

Minimal data set.

(XLSX)</p

Factors associated with changes in viral load in stools.

Factors associated with changes in viral load in stools.</p

Viral load in stools and nasopharyngeal swabs of unvaccinated and vaccinated (at least 1 dose) participants.

The graph presents the median and the minimal to the maximal range of viral load in log10 copies/mL. The significance of the pairwise two-sided t-tests is indicated on top.</p

Baseline characteristics of the participants categorized by sample positivity.

Baseline characteristics of the participants categorized by sample positivity.</p

SARS-CoV-2 PCR test results among COVID-19 participants.

SARS-CoV-2 PCR test results among COVID-19 participants.</p